Non-contact wide angle retina viewing system

ABSTRACT

A retina viewing system and method of using the same includes an ophthalmic microscope, a disposable lens attachment, and an electronic control unit (ECU). The microscope has an optical head and a set of internal focusing lenses, the latter providing the microscope with a variable working distance or focal length. The disposable lens attachment includes a resilient body with a proximal end connected to the optical head and a distal end connected to a high-power/high-diopter distal lens. The ECU executes instructions for viewing a retina or other intraocular anatomy of a patient eye. Execution of the instructions causes the ECU to automatically adjust the variable working distance or focal length of the microscope when viewing an image of the retina through the distal lens.

INTRODUCTION

The present disclosure relates to automated systems and methods forvisualizing the retina and other anatomy of a patient's eye whenperforming an ophthalmic procedure. The intraocular volume of a humaneye is occupied by a transparent gel-like matter referred to as thevitreous body. The retina covers posterior walls of an internal cavityof the eye, i.e., the vitreous cavity, and thereby forms a thin layer ofinterconnected nervous tissue. Light entering the eye passes through thecornea and lens capsule, with zonules and ciliary muscles acting on thelens capsule to focus the admitted light onto the retina. Individual rodand cone photoreceptor cells of the retina react to the admitted lightby generating nerve impulses, which in turn are interpreted by the brainas colors and images. Proper eyesight therefore depends on a healthyretina and viscous body.

Factors such as injury, age, and severe myopia can cause the vitreousbody to separate from the retina. Resulting transient or sustainedtension on the retina by the separating vitreous body may cause a tearin the retina. Likewise, blunt force to the eye or surrounding regionsof the head can directly damage the retina. In order to properlydiagnose retinal tears, vitreous detachment, and other intraocularconditions, a clinician typically employs a high-definition retinaviewing system. Such a system illuminates the vitreous cavity with lightin an eye-safe portion of the electromagnetic spectrum, and thereafterpresents the illuminated anatomy under high magnification. In thismanner, the clinician is afforded a clear view of the retina, macula,vitreous body, and other surrounding tissue. Similar magnificationlevels and high-definition viewing may be employed in pre-operative andpost-operative diagnostic settings.

SUMMARY

Disclosed herein are an improved retina viewing system and anaccompanying method for viewing the retina and other intraocular anatomyof a human eye. The present system is intended to provide a lower cost,non-contact, wide-angle retina viewing solution that eliminates therequirement for manual external focusing control of an accompanyingophthalmic microscope. Additionally, aspects of the present disclosuremay use digital bar coding/serialization or another logic-basedautomation sequence to prevent inadvertent reuse of single-usedisposable components of the retina viewing system as set forth below.

The retina viewing system according to an exemplary embodiment includesan ophthalmic microscope having an optical head, a disposable lensattachment having a high-power/high-diopter distal lens, and anelectronic control unit (ECU). A proximal end of the disposable lensattachment is configured to connect to the optical head of themicroscope, e.g., via magnetic attraction, hook-and-loop connection,adhesives, or direct mechanical engagement. The ECU, which is incommunication with the microscope, is programmed to execute instructionsfor viewing the retina or other intraocular anatomy through operation ofthe distal lens and the microscope during an ophthalmic procedure.

The ophthalmic microscope contemplated herein, which may be digital oranalog in different embodiments, includes a set of internal focusinglenses that collectively provide the microscope with a variable workingdistance or focal length. This feature stands in contrast to typicalophthalmic microscopes of the type characterized by anon-adjustable/fixed working distance, thus necessitating reducinglenses and a clinician's manual involvement in an external focusingaction. The ECU, when informed by the spatial position and power of thedistal lens disposed at a distal end of the disposable lens attachment,automatically controls a focal setting of the internal focusing lenses.The ECU may perform this adjustment automatically in some embodiments,i.e., without intervention or action by the clinician, thus providing an“auto-focus” capability. Such optional auto-focusing control occursafter the disposable lens attachment has been securely connected to theoptical head. Alternatively, the ECU may act as a local controllerproviding control inputs in response to control inputs from theclinician, e.g., operation of a foot pedal.

A method is also disclosed for controlling the retina viewing systemduring an ophthalmic procedure on a patient eye. According to adisclosed exemplary embodiment, the method includes, in response toreceiving of an initiation signal by the ECU, automatically verifying aconnection of a proximal end of a disposable lens attachment to anoptical head of an ophthalmic microscope. As summarized above, themicroscope contemplated herein includes a set of internal focusinglenses providing the microscope with a variable working distance orfocal length. A distal end of the disposable lens attachment isconnected to a high-power/high-diopter distal lens.

In this embodiment, and in response to verifying the connection of theproximal end, the ECU adjusts the variable working distance or focallength of the ophthalmic microscope, autonomously or in response tocontrol inputs from the clinician, to thereby view an image of a retinaof the patient eye through the distal lens using the microscope.

The disposable lens attachment in a particular non-limitingconfiguration includes a high-power/high-diopter distal lens havingrefractive power of about 70 diopters to about 110 diopters, and aconical resilient body. The resilient body has a proximal end configuredto connect to the optical head of an ophthalmic microscope, and a distalend connected to the distal lens. The conical resilient body isconstructed of a resilient material configured to bend and/or collapseaway from the patient eye in the event of contact therewith.

The above-described features and advantages and other possible featuresand advantages of the present disclosure will be apparent from thefollowing detailed description of the best modes for carrying out thedisclosure when taken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of an exemplary ophthalmic procedureconducted using a retina viewing system constructed with a disposablenon-contact lens attachment device in accordance with the presentdisclosure.

FIG. 2 is a schematic illustration of the retina viewing system shown inFIG. 1.

FIG. 3 is a schematic illustration of a telescoping collapsibleembodiment of a disposable non-contact lens attachment device usablewith the system shown in FIG. 2.

FIG. 4 is a schematic perspective view illustration of an alternativeembodiment of the disposable lens attachment device usable with theretina viewing system of FIGS. 1 and 2.

FIG. 5 is a flow chart describing a representative embodiment of amethod for using the retina viewing system of FIG. 2.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described herein. It is to beunderstood, however, that the disclosed embodiments are merely examples,and that other embodiments can take various and alternative forms. TheFigures are not necessarily to scale. Some features may be exaggeratedor minimized to show details of particular components. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a representative basis forteaching one skilled in the art to variously employ the presentdisclosure.

Certain terminology may be used in the following description for thepurpose of reference only, and thus are not intended to be limiting. Forexample, terms such as “above” and “below” refer to directions in thedrawings to which reference is made. Terms such as “front,” “back,”“fore,” “aft,” “left,” “right,” “rear,” and “side” describe theorientation and/or location of portions of the components or elementswithin a consistent but arbitrary frame of reference, which is madeclear by reference to the text and the associated drawings describingthe components or elements under discussion. Moreover, terms such as“first,” “second,” “third,” and so on may be used to describe separatecomponents. Such terminology may include the words specificallymentioned above, derivatives thereof, and words of similar import.

Referring to the drawings, wherein like reference numbers refer to likecomponents, a representative ophthalmic procedure 10 is shownschematically in FIG. 1, during which a clinician 12 is required toprecisely visualize the retina or other intraocular tissue within an eye14 of a patient 140. To that end, the clinician 12 is assisted byhigh-definition multi-dimensional digital viewing capabilities of aretina viewing system 16, with the retina viewing system 16 constructedand controlled as set forth herein. For illustrative clarity, onlyselect components of the retina viewing system 16 are depicted in FIG.1, with the retina viewing system 16 described in greater detail belowwith reference to the remaining Figures.

As described below with reference to FIGS. 2 and 3, the retina viewingsystem 16 utilizes resident internal focusing capabilities of anophthalmic microscope 18, e.g., a digital or analog medical-grademicroscope, to provide a lower-cost, disposable, non-contact option forwide-angle retina viewing. At least some of the attendant benefits ofthe present teachings include the provision of high-power magnificationduring the course of the exemplary ophthalmic procedure 10 of FIG. 1without the need for the clinician 12 to perform external focusingactions and without reducing lenses, or at least reducing the relianceof the clinician 12 on such external focusing actions and hardware.Specific control methodologies are disclosed herein with reference toFIG. 5 for providing improved optical clarity, ease of use, andserialization/traceability.

In a representative embodiment, the ophthalmic procedure 10 depictedschematically in FIG. 1 may be a vitreoretinal surgery or any otherprocedure related to the diagnosis and treatment of disease and/ordamage to the intraocular anatomy of the eye 14. By way of example andnot limitation, such a procedure 10 may encompass the direct repair orreattachment of a torn or separated retina, the performance of avitrectomy, and/or the diagnosis and/or repair of a myriad of otherpossible conditions of the eye 14. Visualization of the target tissueduring the course of the procedure 10 may be enhanced by real-time videobroadcasting via a display monitor 11, such as a medical grade 4K orother ultra-high definition liquid crystal display (LCD) or organiclight-emitting diode (OLED) panel, which is situated within easy view ofthe clinician 12 and other attending personnel within the surgicalsuite.

In preparation for the ophthalmic procedure 10, the patient 140 may becovered by a sterile surgical drape 20, with the drape 20 or anothercovering defining an opening 21 exposing the eye 14. A wire speculum 22or other suitable tool may be used to retain the eye 14 in an open stateduring the procedure 10, during which the clinician 12 may insert aprocedure-specific surgical tool 23 into the above-noted vitreouscavity. Depending on the nature or particular stage of the procedure 10,the surgical tool 23 may be variously embodied as forceps, a bladedvitrectomy probe, a canula, an infusion tool, an endoilluminator, or anyother surgical tool 23 that may be required.

As part of the present approach, the retina viewing system 16 isconfigured for magnifying and clearly visualizing the intraocularanatomy of the eye 14 in real-time so as to aid the clinician 12 andother attending personnel in conducting the ophthalmic procedure 10. Tothat end, the ophthalmic microscope 18 of the retina viewing system 16may be suspended from overhead, e.g., connected to and/or supported by amulti-axis robot 30 (see FIG. 2). In order to function as intended withthe retina viewing system 16 within the scope of the disclosure, themicroscope 18 has a variable as opposed to a fixed working distance, andthus has a variable or adjustable focal length. A task light 70 arrangedon an underside 29 of the microscope 18 or on another suitable surfacemay provide overhead lighting LL to further illuminate the eye 14 andthe surrounding working space.

Those skilled in the art will appreciate that current non-contact,wide-angle disposable retina viewing systems typically utilizefixed-distance microscopes, and thus rely on external focus controlattended to by the clinician 12. For instance, a rotary dial or knob maybe rotated manually or via a surgeon-controlled servomotor to bring theretina into proper focus. A reducing lens used in such systems istypically disposed above patient's cornea, e.g., 150 mm to 175 mm away.Due to the fixed working distance noted above, the reducing lens ismoved via manipulation by the clinician 12 of the above-noted knobsand/or by operation of a footswitch to bring the retina into a desiredfocus.

In contrast, the retina viewing system 16 of the present disclosurereduces and possibly eliminates the need for external focusing and thereducing lens. This in turn eliminates a potentially problematic featurethat at times can be unstable, and that requires additional dexterityand operating time. For instance, disclosed embodiments of the retinaviewing system 16 eliminate the above-noted reducing lens, as well asthe need for external focusing thereof, although the use of a reducinglens is not strictly precluded in the event a particular clinician 12prefers to retain this option. Performance advantages are thus providedvia integration of direct or indirect focus control of a set of internalfocusing lenses 18L of the ophthalmic microscope 18 with other aspectsof the retina viewing system 16. That is, the present approach taps intoand harnesses the focusing capabilities of the ophthalmic microscope 18,for instance digital embodiments thereof, to provide a lower costdisposable option for retina viewing, one that greatly simplifies andenhances vitreoretinal surgical procedures.

Still referring to FIG. 1, the retina viewing system 16 may be attachedto an optical head 24 of the ophthalmic microscope 18 using a mechanicalengagement element, such as is depicted in FIG. 3, or via the forces ofattraction such as magnetic attraction, a hook-and-loop connection, afriction/interference fit, or medical grade adhesives as shown in FIGS.1 and 2. The clinician 12 and/or the multi-axis robot 30 of FIG. 2 mayadjust the spatial position and orientation of the microscope 18relative to a cornea surface of the exposed eye 14. For illustrativeclarity, the microscope 18 and a disposable lens attachment 25 connectedthereto is shown a greater distance away from an actual operatingposition, in which a high-power/high-diopter distal lens 26 of thedisposable lens attachment 25 is typically positioned about 5 mm-10 mmaway from a cornea surface of the eye 14. The need for precise andrepeatable positioning of the distal lens 26 relative to the corneasurface thus lends itself to the integrated precision focusing approachof the present disclosure, with an exemplary method 100 for using theretina viewing system 16 once again described below with reference toFIG. 5.

In the course of performing the exemplary ophthalmic procedure 10 ofFIG. 1, in some embodiments the clinician 12 may elect to view theretina or other target area of the eye 14 through a set of optical eyepieces (not shown). As appreciated in the art, such eye pieces may be anintegral part of certain commercially available medical-grade ophthalmicmicroscopes to provide the clinician 12 or other attending practitionerswith a particular view. Non-limiting exemplary microscopes in thiscategory include the LuxOR® Revalia Ophthalmic Microscope from Alcon,Inc., as well as the OPMI Lumera® 700 from Carl Zeiss Meditec, Inc.Other commercially-available microscopes, such as but not necessarilylimited to the Aesculap AEOS™ Digital Microscope from Aesculap, Inc.,forego use of such eyepieces. Thus, eye pieces may be present or absentfrom the construction of the ophthalmic microscope 18 within the scopeof the present disclosure.

Control surfaces may be present on a pair of control handles 118 of theophthalmic microscope 18, with one such control handle 118 visible fromthe perspective of FIG. 1. Such paddle-like control handles 118 may bealternatively configured as cylindrical bicycle grip-style handles 218as shown in FIG. 2, or as another suitable shape. Once the ophthalmicprocedure 10 is finished, the disposable lens attachment 25 may bequickly and easily detached from the optical head 24 of the microscope18 and discarded, thereby providing the above-noted low-cost disposableoption. A small touchscreen 110 may likewise be used as an additionalcontrol input device to an electronic control unit (ECU 50) of FIG. 2and/or the microscope 18.

With respect to the high-power/high-diopter distal lens 26 used as anintegral component of the disposable lens attachment 25, the term“high-power/high-diopter” refers to an application-suitable level ofmagnification. In a non-limiting example, a refractive power of at least70 diopters may be desirable, with a range of about 70 diopters to about110 diopters possibly being optimal for performing certainrepresentative procedures 10, e.g., a vitreoretinal surgery. The distallens 26 may be aspherical in some embodiments, although this shape isnot strictly necessary. For example, the distal lens 26 may bespherical, in which case spherical aberrations may be corrected insoftware by the ECU 50, using another lens, the microscope 18, etc.

As will be appreciated by those skilled in the art, the distal lens 26is configured to optically invert light from posterior regions of thevitreous cavity of the eye 14, with such light possibly emitted fromwithin the vitreous cavity via endoillumination. The distal lens 26 thusprovides a virtual image of the retina and surrounding tissue. Lightpassing through the distal lens 26 propagates directly to the ophthalmicmicroscope 18 in some embodiments, which would have the benefit ofeliminating intervening reducing lenses of the type typically used withfixed working distance ophthalmic microscopes as described above. Inother embodiments, an optional reducing lens 47 (see FIG. 2) may beused, with such an option providing a different or preferred field ofview.

With respect to the variable working distance/focal length capabilitiesof the ophthalmic microscope 18 contemplated herein for use with theretina viewing system 16 of the present disclosure, the internalfocusing lenses 18L provide a variable working distance, for instanceabout 150 mm to 450 mm in a non-limiting representative embodiment.Ranges falling within these limits may be used in other embodiments,e.g., 150 mm-300 mm or 150 mm-200 mm, with automatic adjustment of theinternal focusing lenses 18L occurring directly or indirectly inresponse to focus control signals (arrow CC₁₈) from the ECU 50, as shownin FIG. 2 and described below. The microscope 18 thus directly focuseson the virtual image produced by the distal lens 26.

The disposable lens attachment 25 is securely but temporarily connectedto the optical head 24 of the ophthalmic microscope 18 via a connectionring 34 disposed at a proximal end E1 of the disposable lens attachment25. In the exemplary embodiment of FIGS. 1 and 2, for instance, thedisposable lens attachment 25 is constructed from a resilient body 28that, in the illustrated representative configuration, is conical inshape and forms a bendable and/or collapsible compliant scaffolding. Inthe event of inadvertent contact between the distal lens 26 and the eye14, the resilient body 28 is configured to telescope, bend, or otherwisecollapse safely away from the eye 14. That is, the resilient body 28 ishighly pliable, bendable, and elastically resilient as opposed to beingstiff and unyielding. Possible constructions include a soft lightweightmolded plastic or silicone rubber, perforated or latticed material, or anetwork of interlaced horizontal and vertical linkages forming asuspension net, a thin disposable membrane, or another suitableconstruction, as well as the telescoping configuration of FIG. 3 asdescribed below.

At the proximal end E1 of the disposable lens attachment 25, theconnection ring 34 may be potted or otherwise connected to the resilientbody 28, e.g., via a cured medical grade adhesive material. Theconnection ring 34 is configured to securely engage the optical head 24of the ophthalmic microscope 18, such as via direct engagement (FIG. 3)or solely via magnetic or other forces of attraction (FIGS. 1 and 2),possible alternatives to the latter including hook-and-loop, adhesivematerials, and friction/interference fit as noted above. Such forces maybe used to advantage to simplify the attachment and disconnectionprocess, with connection possibly aided by structural alignment featureson the microscope 18 and/or the connection ring 34 that collectivelyallow the connection ring 34 to securely lock into place with respect tothe optical head 24.

At a distal end E2 of the disposable lens attachment 25, i.e.,diametrically opposite the proximal end E1/connection ring 34, a smallprotective sleeve 32 constructed of an opaque medical grade polymer ormetal material may be disposed between the distal lens 26 and theresilient body 28 to help reduce glare on the distal lens 26, as well asto facilitate a secure connection of the distal lens 26 to the resilientbody 28. While other shapes and/or structural configurations of theresilient body 28 are possible within the scope of the disclosure, thedepicted conical shape may help prevent an intrusion of dust or debrison the distal lens 26 from above, i.e., from the direction of theophthalmic microscope 18.

Referring briefly to FIG. 3, the resilient body 28 may optionallyinclude a telescoping plurality of resilient bodies 280, i.e., resilientbodies 28A, 28B, and 28C. The resilient bodies 280 are collectivelyconfigured to articulate or pivot with respective to other and thuscollapse away from the patient eye 14 in response to contact therewith.That is, with distal lens 26 attached to the smallest diameter one ofthe resilient bodies 280, i.e., resilient body 28A, any contact with theeye 14 would cause the resilient body 28A to move upward into theslightly larger diameter resilient body 28B, which in turn is urged intothe resilient body 28C in a telescoping manner, as indicated by arrowsDD. Absent contact with the eye 14, forces of gravity would cause theresilient bodies 280 to return to the equilibrium position depicted inFIG. 3.

As shown in FIG. 4, the disposable lens attachment 25 of FIG. 1 may bealternatively embodied as a disposable lens attachment 125 havinganother resilient body 128. As shown, the resilient body 128 is anarticulated mechanism having a plurality of hinged arm segments, shownas respective first and second arm segments 36 and 136. The first armsegment 36 is configured to mechanically engage the optical head 24 ofthe ophthalmic microscope 18 at the proximal end E1, e.g., via fasteners39 and tabular extensions 38.

In the illustrated configuration, the first arm segment 36 defines aY-shaped or forked end 37 which opens to receive the tabular extensions38 and fasteners 39. Additional fasteners 45 may connect the second armsegment 136 to the first arm segment 36, such that fasteners 45 formpivot points allowing the second arm segment 136 to rotate about theaxis of the fastener 45 so as to raise or lower the distal lens 26 thatis disposed at the distal end E2. In this embodiment, a support member35 such as a cylindrical or generally conical metal or plastic may beused to provide a suitable mass for connecting the distal lens 26 andthe protective sleeve 32 to the distal end E2.

Referring now to FIG. 2, the above-described ophthalmic microscope 18may be optionally coupled to an end-effector 31 of the multi-axis robot30 noted briefly above, with such coupling indicated via double-headedarrow CC. As appreciated, such a robot 30 typically includes a base 40connected to a set of wheels 41. To provide multiple degrees of freedomof movement, the robot 30 is equipped with a plurality of linkages 42,with the various linkages 42 being interconnected via correspondingrevolute joints 44. The base 40 may be connected to the wheels 41 tofacilitate relocation or movement of the robot 30 within a facility or agiven surgical suite.

Within the construction of the robot 30, therefore, each revolute joint44 may be actively driven in some embodiments by a rotary actuator (notshown), e.g., a servo motor, to provide multiple control degrees offreedom, including forward/backward, vertical, and horizontaltranslation as well as pitch, yaw, and roll orientation of theend-effector 31. Other embodiments may enable the clinician 12 topassively reposition the robot 30 without the aid of such actuators.Collectively, the revolute joints 44 and the various linkages 42 allowthe end-effector 31 and components of the retina viewing system 16connected thereto to move, or to be moved, within a defined workspace.In this manner, the robot 30 is able to facilitate precise positioningof the distal lens 26 relative to a cornea surface 15 of the eye 14, asindicated by arrows AA and BB.

As shown in FIG. 2, motion control of the ophthalmic microscope 18 andthe connected retina viewing system 16 may be commanded by the clinician12 of FIG. 1 using different control inputs. For example, to command therobot 30 to position the optical head 24 at a particular orientation andspatial position in a three-dimensional Cartesian frame of reference,the clinician 12 could depress a foot pedal 60 and/or activate a keypad(not shown) disposed on the control handles 118 or 218 of the ophthalmicmicroscope 18, with the latter configuration depicted in FIG. 2.Additional control inputs may be entered via the touch screen 110.

Software programming for the robot 30 may in some embodimentsautomatically identify the eye 14, e.g., using a machine visionalgorithm, a neural network, proximity sensing, etc., and thereafterautomatically position and orient the retina viewing system 16, and inparticular the distal lens 26 thereof, a predetermined distance awayfrom the cornea surface 15, typically about 5-10 mm away as appreciatedin the art. Such software can therefore communicate with residentcontrol logic of the ophthalmic microscope 18 to automatically adjustthe working distance/focal length of the internal focusing lenses 18Lthereof without required intervention by the clinician 12.

Additionally, using control inputs from the foot pedal 60, the controlhandles 118 or 218, and/or the touchscreen 110 mounted near or on theretina viewing system 16, the clinician 12 is able to turn on the light70 (see FIG. 1) on the underside 29 of the ophthalmic microscope 18 tocause the microscope 18 to emit the above-noted light beam LL, or toautomatically retract the optical head 24 by a predetermined distance,e.g., 50-75 mm, and/or to remove the retina viewing system 16 from viewwhen working on the anterior portion of the eye 14. When the clinician12 is ready to return to a posterior view, the clinician 12 could simplyclick the retina viewing system 16 into place on the optical head 24 andthereafter use the same control inputs.

Using position sensing, machine vision, and/or artificial intelligenceof the type noted above, the ophthalmic microscope 18, controlled insome respect via the ECU 50, could automatically detect the retinaviewing system 16 or otherwise determine that the retina viewing system16 has been successfully mounted to the optical head 24. Machine visioncould likewise be used to detect the retina viewing system 16 beingattached or detached. In response, the ECU 50 may command the robot 30to move the microscope 18 up or down, and/or position the distal lens 26at the preset 5-10 mm distance above the cornea 15. Without an externalfocus input or any other input being required from the clinician 12,optional auto-focus control/adjustment of the internal focusing lenses18L by the ECU 50 as part of the method 100 shown in FIG. 5 could thusbe used to obtain the proper focus so that the clinician 12 is ready toattend to the operation.

The retina viewing system 16 of the present disclosure is intended to besingle-use, and thus is configured to be disposable. To that end, aserialization strategy may be enforced by the ECU 50 to protect againstinadvertent reuse of a given retina viewing system 16. Such a strategymay be facilitated by existing CMOS or other cameras of the ophthalmicmicroscope 18. For example, a scannable bar code, QR code, or otherunique serial identifier code 33 may be printed on, adhered to, orotherwise incorporated into the retina viewing system 16 and/or itshermetically sealed packaging (not shown) to log usage and preventreuse. Exemplary locations for imprinting the serial identifier code 33include the connection ring 34, which from a top view may provide asufficiently wide and planar surface for printing or attaching a labelcontaining the serial identifier code 33, or a surface of the protectivesleeve 32. Other approaches such as RFID tags may be used in otherembodiments.

To enable the various software-based control aspects of the presentdisclosure, the ECU 50 is in networked communication with the ophthalmicmicroscope 18 and the robot 30, with such two-way communicationindicated by double-headed arrow CC₃₀ in FIG. 3. The ECU 50 may beconfigured to execute computer-readable code or instructions embodyingthe method 100 for performing one or more tasks involving use of theretina visualization system, with an exemplary embodiment of the method100 depicted in FIG. 5 and described below. Although the ECU 50 is shownschematically as a unitary device for illustrative simplicity, the ECU50 may include one or more networked computer devices, along withassociated computer-readable media or memory (M), including anon-transitory (e.g., tangible) medium that participates in providingdata/instructions that may be read by one or more processors (P).

The memory (M) may take many forms, including but not limited tonon-volatile media and volatile media. As will be appreciated,non-volatile media may include optical and/or magnetic disks and otherpersistent memory, while volatile media may include dynamicrandom-access memory (DRAM), static RAM (SRAM), etc., any or all whichmay constitute a main memory. Communication with the ophthalmicmicroscope 18 and the robot 30 may be achieved via a networkedconnection to input/output (I/O) circuitry of the ECU 50. Other hardwarenot depicted but well established in the art may be included as part ofthe ECU 50, including but not limited to a local oscillator orhigh-speed clock, signal buffers, digital signal filters, etc.

Referring to FIG. 5, the method 100 noted above in an exemplaryembodiment may commence at sequential block B102 with initialization ofthe retina viewing system 16. For example, the clinician 12 may turn onthe robot 30 and the ophthalmic microscope 18 in preparation for theophthalmic procedure 10 shown in FIG. 1. Block B102 may entail coarseautomatic or manual positioning of the robot 30 and the microscope 18relative to an operating position to be occupied by the patient 140 ofFIG. 1. Initialization may result in receipt of an initiation signal(arrow CC_(IN)) by the ECU 50, which could ultimately respond byprompting for connection of the disposable lens attachment 25 or 125 tothe optical head 24 as set forth below. The method 100 proceeds to blockB104 after initialization is complete.

At block B104, the clinician 12 opens a hermetically sealed packagecontaining the above-described disposable lens attachment 25 of FIGS.1-3 or the alternative disposable lens attachment 125 of FIG. 4. As partof the method 100 of FIG. 5, the package and/or the disposable lensattachment 25 or 125 may include a unique serial identifier code 33. Insuch an embodiment, the clinician 12 may scan the serial identifier code33 to thereby log the usage of the disposable lens attachment 25 or 125in memory (M) or a database. In a possible embodiment, onboard CMOScameras or other onboard optical scanning capabilities of the ophthalmicmicroscope 18 may be used to scan the serial identifier code 33 as ascanned input, in which case the microscope 18 could transmit thescanned input to the ECU 50, or scanning may be achieved using anexternal scanning device. The method 100 then proceeds to block B106.

At block B106, the ECU 50 compares the serial identifier code from blockB104 as a scanned input to a preloaded list of previously usedidentifier codes. Such a list may be stored or prepopulated in thememory (M) of the ECU 50, for instance in a lookup table. Each time aclinician 12 opens and scans a respective serial identifier code 33 fora respective disposable lens attachment 25 or 125, the serial identifiercode is recorded in memory (M) for later comparison. The method 100proceeds to block B108 when the serial identifier code appears on thepreloaded list, and to block B110 in the alternative when the serialidentifier code does not appear on the preloaded list.

At block B108, as a control action the ECU 50 may register/record anerror code in memory (M) that is indicative of the prior use of thedisposable lens attachment 25 or 125, and thereafter activating an audioand/or visual indicator via the ECU 50. That is, responsive to recordingthe error code, the ECU 50 may alert the clinician 12 that thedisposable lens attachment 25 or 125, or at least its associated serialidentifier code, has been previously used. For instance, the ECU 50 mayilluminate a red light or other visual indicator, or may display acorresponding message on the display screen 11 and/or 110 of FIGS. 1 and2, and/or activate an audible alarm indicative of the prior use of thedisposable lens attachment 25. The method 100 then repeats block B104.

Block B110 includes confirming the scan result from block B104, e.g., byrecording a bit code indicative of no prior use of the disposable lensattachment 25 or 125, via the ECU 50, with this control action possiblyfollowed by a confirmation signal. For instance, the ECU 50 mayautomatically activate an audio and/or visual indicator as a controlaction, such as by illuminating a green light or other visual indicatordevice on the display monitor 11, the touch screen 110, and/or aseparate device. The ECU 50 may also display a corresponding message onthe display monitor 11 and/or touch screen 110 of respective FIGS. 1 and2, and/or activate an audible chime or tone indicative of no detectedprior use of the disposable lens attachment 25 or 125.

Block B110 thus includes automatically verifying proper connection ofthe proximal end E1 of the disposable lens attachment 25 or 125 to theoptical head 24 of the ophthalmic microscope 18, such as using machinevision capabilities to discern accurate positioning and/or by receivinga confirmation signal (arrow CC_(IN)) from a control panel indicative ofthe proper connection. Such confirmation would occur in conjunction witha bit code indicating no prior use of the disposable lens attachment 25or 125, with the control panel possibly including the above-describedcontrol handles 118 or 218, the touch screen 110, etc. The method 100then proceeds to block B112.

Block B112 entails connecting the disposable lens attachment 25 or 125to the optical head 24 of the ophthalmic microscope 18. Block B112 mayinclude placing the disposable lens attachment 25, in the FIG. 1 andFIG. 2 embodiment, adjacent to the optical head 24 and allowing theforces of magnetic attraction from the magnetic connector ring 34, orhook-and-loop attraction or forces of friction or adhesion, to securethe disposable lens attachment 25 in place. In the alternativeembodiment of FIG. 4, the disposable lens attachment 125 may bemechanically coupled to the optical head 24. The method 100 thenproceeds to block B114.

Block B114 includes commencing the ophthalmic procedure 10 of FIG. 1. Ina possible embodiment, block B114 may include inputting an initiationsignal to the ECU 50 indicative of a desire of the clinician 12 to beginthe procedure 10. In response, the ECU 50 may automatically command therobot 30 of FIG. 2 to position the disposable lens attachment 25 or 125,and in particular the distal lens 26 thereof, at the predetermineddistance of about 5-10 mm away from the cornea surface 15 of the eye 14shown in FIG. 2.

Once so positioned, the ECU 50 may then adjust the variable workingdistance or focal length of the ophthalmic microscope 18 via directauto-focusing control of its internal focusing lenses 18L, or via amotor-driven response to inputs from the clinician 12. That is, thecontrol response by the ECU 50 relative to the focal setting of themicroscope 18 may occur fully autonomously or only in response to inputsignals from a clinician input device, e.g., the foot pedal 60, controlhandles 118 or 218, or the touch screen 110. This enables the clinician12 to view an image of a retina or other intraocular structure of thepatient eye 14 through the distal lens 26 using the microscope 18. Themethod 100 thereafter proceeds to block B116.

At block B116, the clinician 12 performs the ophthalmic procedure 10until its completion. Inputs to the ECU 50 during the course of theprocedure 10 may be provided via the control handles 118 or 218 of FIGS.1 and FIG. 2, respectively, the touch screen 110 and/or the foot pedal60 of FIG. 2, etc., with the ECU 50 reacting by transmittingcorresponding position control signals (arrow CC₃₀) to the robot 30. Themethod 100 proceeds to block B118 when the corresponding positioncontrol signals (arrow CC₃₀) have been transmitted to the robot 30.

Block B118 may include determining whether the ophthalmic procedure 10is complete. For example, upon completion of the procedure 10 the ECU 50may receive a completion signal (arrow CC_(COMP) of FIG. 2) indicativeof a desire of the clinician 12 to end the procedure 10. In variousembodiments, generation of the completion signal may result when theclinician 12 touches a corresponding “end procedure” icon on the displayscreen 110, or when the clinician 12 moves or commands movement of theophthalmic microscope 18 a predetermined distance away from the patient140. In response to either input, the ECU 50 may activate some or all ofthe revolute joints 44 of the robot 30 to assist in the relocation ofthe ophthalmic microscope 18. The method 100 then proceeds to blockB120.

Block B120 entails removing the disposable lens attachment 25 or 125from the optical head 24. The clinician 12 can then discard thedisposable lens attachment 25 or 125. The method 100 is then complete,beginning anew at block B102 for a subsequent ophthalmic procedure 10.

The retina viewing system 16 described herein therefore provides alower-cost, non-contact, wide-angle retina viewing option. Simplifiedutility is provided by virtue of eliminating the need for the surgeon 12to externally focus the ophthalmic microscope 18. That is, byconfiguring the microscope 18 and via programming of the ECU 50 to placethe virtual image from the distal lens 26 within the variable workingdistance of the microscope 18, the present solution eliminates the needto externally focus via intervening reducing lenses. As will beappreciated by those skill in the art, elimination of the external focuscontrol requirement shortens the length of the ophthalmic procedure 10.This in turn, taken in conjunction with the reuse-preventingserialization strategies presented above, may help reduce the overallrisk of surgical complications. These and other attendant benefits willbe readily appreciated by those of ordinary skill in the art in view ofthe foregoing disclosure.

The detailed description and the drawings are intended to be supportiveand descriptive of the disclosure, but the scope of the disclosure isdefined solely by the claims. While some of the best modes and otherembodiments for carrying out the claimed disclosure have been describedin detail, various alternative designs and embodiments exist forpracticing the disclosure defined in the appended claims.

Furthermore, the embodiments shown in the drawings or thecharacteristics of various embodiments mentioned in the presentdescription are not necessarily to be understood as embodimentsindependent of each other. Rather, it is possible that each of thecharacteristics described in one of the examples of an embodiment can becombined with one or a plurality of other desired characteristics fromother embodiments, resulting in other embodiments not described in wordsor by reference to the drawings. Accordingly, such other embodimentsfall within the framework of the scope of the appended claims.

What is claimed is:
 1. A retina viewing system comprising: an ophthalmicmicroscope having an optical head and a set of internal focusing lenses,the set of internal focusing lenses providing the ophthalmic microscopewith a variable working distance or focal length; a disposable lensattachment having a resilient body and a high-power/high-diopter distallens, wherein a proximal end of the disposable lens attachment isconnected to the optical head, and a distal end of the disposable lensattachment is connected to the distal lens; and an electronic controlunit (ECU) in communication with the ophthalmic microscope andprogrammed to execute instructions for viewing a retina of a patienteye, wherein execution of the instructions by a processor of the ECUcauses the ECU to focus the internal focusing lenses, autonomously or inresponse to input signals from a clinician input device, to therebyadjust the variable working distance or focal length of the ophthalmicmicroscope when viewing an image of the retina through the distal lens.2. The retina viewing system of claim 1, further comprising: amulti-axis robot in communication with the ECU, wherein execution of theinstructions by the processor causes the multi-axis robot toautomatically position the ophthalmic microscope such that the distallens is a predetermined distance away from a cornea surface of thepatient eye.
 3. The retina viewing system of claim 1, wherein theresilient body of the disposable lens attachment has a conical shape,and is constructed of a flexible material configured to bend and/orcollapse away from the patient eye in response to contact therewith. 4.The retina viewing system of claim 3, wherein the resilient bodyincludes a telescoping plurality of resilient bodies collectivelyconfigured to collapse away from the patient eye in response to contacttherewith.
 5. The retina viewing system of claim 1, wherein theresilient body includes a plurality of hinged arm segments, including afirst arm segment configured to mechanically engage the optical head anda second arm segment having a distal end to which is connected thedistal lens.
 6. The retina viewing system of claim 1, wherein thedisposable lens attachment includes an attachment ring forming theproximal end of the resilient body, and wherein the disposable lensattachment is magnetically connected to the optical head of theophthalmic microscope.
 7. The retina viewing system of claim 1, whereinthe distal lens has a refractive power level of 70 diopters to 110diopters.
 8. The retina viewing system of claim 1, wherein a surface ofthe disposable lens attachment is imprinted with a unique serialidentifier code configured to prevent reuse of the disposable lensattachment.
 9. The retina viewing system of claim 8, wherein to preventthe reuse of the disposable lens attachment, the ECU is configured to:receive a scanned input of the serial identifier code; and in responseto the scanned input matching a previously recorded serial identifiercode, to execute a control action preventing the reuse of the disposablelens attachment.
 10. The retina viewing system of claim 9, wherein theophthalmic microscope is configured to automatically scan the serialidentifier code to generate the scanned input, and to thereaftertransmit the scanned input to the ECU.
 11. A method for controlling aretina viewing system during an ophthalmic procedure on a patient eye,the method comprising: in response to receiving an initiation signal byan electronic control unit (ECU), automatically verifying a connectionof a proximal end of a disposable lens attachment to an optical head ofan ophthalmic microscope, wherein the ophthalmic microscope includes aset of internal focusing lenses providing the ophthalmic microscope witha variable working distance or focal length, and wherein a distal end ofthe disposable lens attachment is connected to a high-power/high-diopterdistal lens; and in response to verifying the connection of the proximalend, automatically adjusting the variable working distance or focallength of the ophthalmic microscope via the ECU, autonomously or inresponse to input signals from a clinician input device, to thereby viewan image of a retina of the patient eye through the distal lens usingthe ophthalmic microscope.
 12. The method of claim 11, wherein the ECUis in communication with a multi-axis robot, the method furthercomprising, while the ophthalmic microscope is coupled to anend-effector of the multi-axis robot: automatically positioning theophthalmic microscope and the disposable lens attachment viatransmission of position control signals to the multi-axis robot by theECU, such that the distal lens is 5 mm to 10 mm away from a corneasurface of the patient eye.
 13. The method of claim 11, whereinautomatically verifying the connection of the proximal end of thedisposable lens attachment includes receiving a confirmation signal froma control panel indicative of the connection via the ECU.
 14. The methodof claim 11, wherein the disposable lens attachment is imprinted with aunique serial identifier code, the method further comprising: receivinga scanned input of the unique serial identifier code via the ECU; andexecuting a control action in response to the scanned input matching apreviously recorded serial identifier code, wherein the control actionis directed toward preventing reuse of the disposable lens attachment.15. The method of claim 14, further comprising: scanning the identifiercode via the ophthalmic microscope to generate the scanned input, andthereafter transmitting the scanned input to the ECU.
 16. The method ofclaim 14, wherein executing the control action includes registering orrecording an error code in memory of the ECU that is indicative of theprior use of the disposable lens attachment, and thereafter activatingan audio and/or visual indicator via the ECU.
 17. A disposable lensattachment for use with a retina viewing system having an ophthalmicmicroscope with an optical head, the disposable lens attachmentcomprising: a high-power distal lens having refractive power of 70diopters to 110 diopters; and a conical resilient body having a proximalend configured to connect to the optical head of the ophthalmicmicroscope, and a distal end connected to the distal lens, wherein theconical resilient body is constructed of a resilient material configuredto collapse away from the patient eye in the event of contact therewith.18. The disposable lens attachment of claim 17, wherein the conicalresilient body is constructed of a flexible perforated or latticedmaterial.
 19. The disposable lens attachment of claim 17, furthercomprising: a magnetic attachment ring connected to the conicalresilient body, and configured to magnetically connect to the opticalhead.
 20. The disposable lens attachment of claim 19, wherein themagnetic attachment ring is imprinted with a unique serial identifiercode configured to prevent reuse of the disposable lens attachment.